.box1 .box2 {
  background-color: aliceblue;
}
.box1 > .box3 {
  background-color: aquamarine;
}
.box1:hover {
  background-color: black;
}
div .box1 {
  width: 100px;
}
.p1,
.p2 {
  width: 100px;
  height: 200px;
}
.p2 {
  color: red;
}
.p3 {
  width: 100px;
  height: 200px;
}
div {
  width: 200px;
  height: 100px;
  border: 1px solid red;
}
div {
  width: 200px;
  height: 100px;
  border: 1px solid red;
}
